The oldest known residency of Kos goes back to the Bronze age (2300 -2000BC) and was traced to the hill Seragion(today’s old town) where part of a settlement and fortress were found. During the Minoan domination in the Aegean, people settled and populated widely in Kos. Because of the Minoan settlement Kos gained a crucial position in the network of commercial routes to the East. The prosperity and blossoming of the settlement is illustrated in the “New Catalogue” of the Iliada (676-680)

Στους ιστορικούς χρόνους, στον ύστερο 10ο π.Χ. αι. εγκαθίστανται οι Δωριείς άποικοι στο νησί, οι οποίοι σύμφωνα με τον Hρόδοτο (7.99) προέρχονταν από την Αργολίδα.  Στην Αρχαϊκή περίοδο η Κως συμμετέχει στη Δωρική Εξάπολη μαζί με τις τρεις πόλεις της Ρόδου (Λίνδος, Iαλυσσός και  Kάμιρος),

The first mention of the early Christian period in Kos is connected to the visit of the disciple Paul which is mentioned in the book of Paul. This was recorded in the minutes of the first Ecumenical Synod of Nice in 325 and was signed by the bishop of Kos Melifron.